<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        //（身高-108）*2=体重
        var height = parseFloat(prompt("请输入身高"));
        var p = parseFloat(prompt("请输入体重"));

        var result = (height - 108) * 2;

        if (p - result > 10) {
            alert("超重");
        }else if (p - result < 0) {//100  120 
            alert("偏瘦")
        }else{
            alert("标准体重")
        }
    </script>
</body>
</html>